Transactional support in hardware for lock-free shared data structures using transactional memory is described in M. Herlihy and J. Moss, Transactional memory: Architectural support for lock-free data structures, Proceedings of the 20th Annual International Symposium on Computer Architecture 20, 1993 (Herlihy and Moss). This approach describes a set of extensions to existing multiprocessor cache coherence protocols that enable such lock free access. Transactions using a transactional memory are referred to as transactional memory transactions or lock free transactions herein.